Is it possible to get "poisoned" by too much sun?

No. Although people refer to a severe sunburn as "sun poisoning," there's no such thing.

Some people develop skin rashes called photodermatosis when they are exposed to intense sunlight. The most common of these is a polymorphous light eruption (PMLE), which typically has red bumps or blisters that itch or burn and sometimes brings on chills, headache, and nausea. About 10% to 20% of the U.S. population develops this condition, most often in the early spring when their first intense sun exposure of the year occurs. Among the most susceptible are people who vacation in tropical locales during the winter months.

Some people also develop photodermatosis because they're taking certain medications (including some antibiotics and blood pressure medications) or using certain kinds of lotions (such as products with alpha- or beta-hydroxy acids or retinoids, a derivative of vitamin A).

Prevention is simple: Wear protective clothing and a broad-spectrum sunscreen when you're outdoors. Avoid the sun between 10 a.m. and 2 p.m., and if you do develop PMLE, see your doctor, who may suggest you apply over-the-counter creams with steroids to your bumps or blisters to help them heal.